# US 11,029,360 B2 · Electric current protection circuit and method of using same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,029,360 B2
- Document ID: US11029360B2
- Status: Granted
- Kind: B2
- Application number: 16/718,965
- Filed: 2019-12-18
- Published: 2020-07-02
- Granted: 2021-06-08
- Earliest claimed: 2018-12-30
- Assignees: Vitesco Technologies USA, LLC
- Applicants: Vitesco Technologies USA, LLC
- Inventors: Robert Arthur Bonetti
- Web page: https://patentgrep.com/patent/US11029360B2

## CPC

- G01R 31/3277: {of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches}
- G01R 31/364: Battery terminal connectors with integrated measuring arrangements
- B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H)
- B60L 3/12: Recording operating variables {; Monitoring of operating variables}
- B60L 58/12: responding to state of charge [SoC]
- B60L 58/20: having different nominal voltages
- G01R 31/2863: {Contacting devices, e.g. sockets, burn-in boards or mounting fixtures (in general G01R1/04)}
- G01R 31/3278: {of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002)}
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A protection device for a vehicle electrical system, including a battery pack having at least one contactor. A microcontroller generates a test pulse at a pulse output thereof and a sense input terminal. The microcontroller has at least one output coupled to the control terminal of the at least one contactor. A first capacitor has a terminal coupled to a first terminal of the at least one contactor; a second capacitor having a terminal coupled to a second terminal of the at least one contactor; and circuitry coupled between the microcontroller and the first and second capacitors. The circuitry reflects the test pulse to the sense input terminal if each contactor is open when the microcontroller applies a contactor opening voltage to the contactor control terminal, and presents a signal different from the reflected test pulse to the sense input terminal of the microcontroller if any contactor is welded shut.

## Claims

### Claim 1

A protection device for protecting an electrical system in a vehicle, the electrical system including a battery pack having at least one contactor, and a high voltage bus connected to the battery pack, the protection device comprising:
a microcontroller which generates test pulses at a pulse output terminal thereof and includes a sense input terminal, the microcontroller having additional output terminals coupled to a control terminal of the at least one contactor;
a first capacitor having a first terminal coupled to a first terminal of the at least one contactor;
a second capacitor having a first terminal coupled to a second terminal of the at least one contactor; and
circuitry coupled between the microcontroller and the first and second capacitors, the circuitry having an input terminal connected to the pulse output terminal of the microcontroller and an output terminal connected to the sense input terminal of the microcontroller, the circuitry reflecting the test pulses to the sense input terminal of the microcontroller if each contactor is open when the microcontroller applies a contactor opening voltage to the control terminal of the at least one contactor to open same, and presenting a signal different from the reflected test pulses to the sense input terminal of the microcontroller if any contactor is welded shut when the microcontroller applies the contactor opening voltage to the control terminal of the at least one contactor.

### Claim 2 (depends on 1)

The protection device of claim 1, wherein the circuitry is powered by a voltage supply, and the circuitry charges the first and second capacitors when any contactor is closed and does not charge the first and second capacitors when each contactor is open, the first and second capacitors being coupled to the sense input terminal of the microcontroller such that a voltage at the sense input terminal of the microcontroller corresponds to a voltage across one or more of the first capacitor and the second capacitor.

### Claim 3 (depends on 2)

The protection device of claim 2, wherein the circuitry comprises:
a first transistor having a first conduction terminal coupled to the voltage supply, a second conduction terminal coupled to a second terminal of the first capacitor, and a control terminal;
a second transistor having a first conduction terminal coupled to the control terminal of the first transistor, a second conduction terminal coupled to a second terminal of the second capacitor, and a control terminal coupled to the pulse output terminal of the microcontroller; and
a resistor coupled between the second terminal of the first capacitor and a reference voltage, a voltage appearing at the second terminal of the first capacitor being coupled to the sense input terminal of the microcontroller.

### Claim 4 (depends on 3)

The protection device of claim 3, wherein when each contactor is open, the first capacitor and the second capacitor are disconnected from each other and creates an open circuit along an electrical path defined along the second conduction terminal of the first transistor, the first capacitor, the second capacitor and the reference voltage, and when any contactor is closed, the electrical path is closed.

### Claim 5 (depends on 2)

The protection device of claim 2, wherein the microcontroller is configured such that, based upon the voltage at the sense input terminal of the microcontroller, the microcontroller determines whether any contactor is welded closed and whether each contactor is open.

### Claim 6 (depends on 5)

The protection device of claim 5, wherein based upon the voltage at the sense input terminal of the microcontroller, the microcontroller is further configured to determine whether any current leakage exists across the at least one contactor.

### Claim 7 (depends on 6)

The protection device of claim 6, wherein based upon the voltage at the sense input terminal of the microcontroller, the microcontroller is further configured to determine an amount of current leakage across at least one contactor.

### Claim 8 (depends on 1)

The protection device of claim 1, wherein the at least one contactor of the battery pack comprises a plurality of contactors, each contactor having a first terminal coupled to the first terminal of the first capacitor and a second terminal coupled to the first terminal of the second capacitor.

### Claim 9 (depends on 1)

The protection device of claim 1, wherein when each contactor is open, the first capacitor and the second capacitor are disconnected from each other and creates an open circuit along an electrical path defined along a power supply which powers the circuitry, the first capacitor, the second capacitor and a ground reference, and when any contactor is closed, the electrical path is closed.

### Claim 10

A protection device for protecting an electrical system in a vehicle, the electrical system including a battery pack having at least one contactor, and a high voltage bus connected to the battery pack, the protection device comprising:
a microcontroller generates test pulses at a pulse output terminal thereof and includes a sense input terminal, the microcontroller having additional output terminals coupled to a control terminal of the at least one contactor;
a first capacitor having a first terminal coupled to a first terminal of the at least one contactor;
a second capacitor having a first terminal coupled to a second terminal of the at least one contactor; and
circuitry coupled between the microcontroller and the first and second capacitors, the circuitry having an input terminal connected to the pulse output terminal of the microcontroller and an output terminal connected to the sense input terminal of the microcontroller, the circuitry reflecting the test pulses to the sense input terminal of the microcontroller if each contactor is open when the microcontroller applies a contactor opening voltage to the control terminal of the at least one contactor to open same, and presenting a signal different from the reflected test pulses to the sense input terminal of the microcontroller if any contactor is welded shut when the microcontroller applies the contactor opening voltage to the control terminal of the at least one contactor, the first and second capacitors being series connected and the at least one contactor providing an electrical connection between the first and second capacitors when the at least one contactor is closed and an open connection between the first and second capacitors when each contactor is opened.

### Claim 11 (depends on 10)

The protection device of claim 10, wherein the circuitry is powered by a voltage supply, and the circuitry charges the first and second capacitors to at or near the voltage supply when any contactor is closed and does not charge the first and second capacitors when each contactor is open, the first and second capacitors being coupled to the sense input terminal of the microcontroller such that a voltage at the sense input terminal of the microcontroller corresponds to a voltage across one or more of the first capacitor and the second capacitor.

### Claim 12 (depends on 11)

The protection device of claim 11, wherein the circuitry comprises:
a first transistor having a first conduction terminal coupled to the voltage supply, a second conduction terminal coupled to a second terminal of the first capacitor, and a control terminal;
a second transistor having a first conduction terminal coupled to the control terminal of the first transistor, a second conduction terminal coupled to a second terminal of the second capacitor, and a control terminal coupled to the pulse output terminal of the microcontroller; and
a resistor coupled between the second terminal of the first capacitor and a reference voltage, a voltage appearing at the second terminal of the first capacitor being coupled to the sense input terminal of the microcontroller.

### Claim 13 (depends on 12)

The protection device of claim 12, wherein when each contactor is open, the first capacitor and the second capacitor are disconnected from each other and creates an open circuit along an electrical path defined along the second conduction terminal of the first transistor, the first capacitor, the second capacitor and the reference voltage, and when any contactor is closed, the electrical path is closed.

### Claim 14 (depends on 11)

The protection device of claim 11, wherein the microcontroller is configured such that, based upon the voltage at the sense input terminal of the microcontroller, the microcontroller determines whether any contactor is welded closed and whether each contactor is open.

### Claim 15 (depends on 14)

The protection device of claim 14, wherein based upon the voltage at the sense input terminal of the microcontroller, the microcontroller is further configured to determine whether any current leakage exists across the at least one contactor.

### Claim 16 (depends on 15)

The protection device of claim 15, wherein based upon the voltage at the sense input terminal of the microcontroller, the microcontroller is further configured to determine an amount of current leakage across at least one contactor.

### Claim 17 (depends on 10)

The protection device of claim 10, wherein the at least one contactor of the battery pack comprises a plurality of contactors, each contactor having a first terminal coupled to the first terminal of the first capacitor and a second terminal coupled to the first terminal of the second capacitor.

### Claim 18 (depends on 10)

The protection device of claim 10, wherein when each contactor is open, the first capacitor and the second capacitor are disconnected from each other and creates an open circuit along an electrical path defined along a power supply which powers the circuitry, the first capacitor, the second capacitor and a ground reference, and when any contactor is closed, the electrical path is closed.